Question

我有一个ruby应用程序，其中有帖子和类似模型。我希望能够单击一个喜欢按钮，然后刷新该帖子的喜欢数目。为此，我正在使用ajax。

我的问题是我如何才能在我的部分html文档中计算帖子的点赞次数。目前，我的_show.html.erb中的代码如下：

<%= @post.likes.all.count %>

我要在index.html.erb中显示代码的div看起来像这样：

<div>
        Likes: <div id="<% post.id %>_likes_output", local: :post></div>
</div>

我的create.js.erb看起来像这样：

$(document.getElementById("<%@post%> _likes_output").innerHTML = "<%= render partial: "likes/show", local: :post %>");

“我的喜欢”创建方法如下：

def create
  @user = current_user.id
  @post = params[:post_id]
  likes = {user_id: @user, post_id: @post}
  @like = Like.new(likes)

  # a new entry in the likes table gets created
  if @like.save!
  else
    flash[:alert] = "Something went wrong"
  end
end

此刻我出现以下错误：

Started POST "/posts/13/likes" for ::1 at 2019-03-22 11:38:28 +0100
Processing by LikesController#create as JS
  Parameters: {"post_id"=>"13"}
  User Load (0.2ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = ? ORDER BY "users"."id" ASC LIMIT ?  [["id", 1], ["LIMIT", 1]]
  ↳ app/controllers/likes_controller.rb:4
   (0.0ms)  begin transaction
  ↳ app/controllers/likes_controller.rb:10
  Post Load (0.2ms)  SELECT  "posts".* FROM "posts" WHERE "posts"."id" = ? LIMIT ?  [["id", 13], ["LIMIT", 1]]
  ↳ app/controllers/likes_controller.rb:10
  User Load (0.1ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = ? LIMIT ?  [["id", 1], ["LIMIT", 1]]
  ↳ app/controllers/likes_controller.rb:10
  Like Create (0.3ms)  INSERT INTO "likes" ("created_at", "updated_at", "user_id", "post_id") VALUES (?, ?, ?, ?)  [["created_at", "2019-03-22 10:38:28.067946"], ["updated_at", "2019-03-22 10:38:28.067946"], ["user_id", "1"], ["post_id", "13"]]
  ↳ app/controllers/likes_controller.rb:10
   (1.0ms)  commit transaction
  ↳ app/controllers/likes_controller.rb:10
  Rendering likes/create.js.erb
  Rendered likes/_show.html.erb (21.0ms)
  Rendered likes/create.js.erb (38.8ms)
Completed 500 Internal Server Error in 91ms (ActiveRecord: 1.8ms)



ActionView::Template::Error (undefined method `likes' for "13":String
Did you mean?  lines):
    1: <%= @post.likes.all.count %>

app/views/likes/_show.html.erb:1:in `_app_views_likes__show_html_erb___2777362880017156755_70224479796840'
app/views/likes/create.js.erb:3:in `_app_views_likes_create_js_erb__712898782247662482_70224408518740'

请让我知道您是否还需要其他东西。非常感谢！

Answer 1

@ flo3719您的代码中可能还存在其他问题，但是您提到的ActionView::Template::Error (undefined method 'likes' for "13":String是由罪魁祸首行@post = params[:post_id]引起的，由于这一行，您的@post对象包含{{ 1}}。

您应该使用以下方法从数据库中找到您的帖子：

"13"

用下面的代码替换@post = Post.find_by_id(params[:post_id])

@post = params[:post_id]

Answer 2

您的<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script> <div id="mobile-nav" class="sidenav" style="height: 0;"> <div id="mobile-nav-content"> <nav> <ul> <li><a href="#home">Casa</a></li> <li><a href="#about">Sobre Mi</a></li> <li><a href="#services">Servicio</a></li> <li><a href="#gallery">Galería</a></li> <li><a href="#contact">Contacto</a></li> </ul> </nav> </div> </div> <div id="desktop-navbar"> <div id="desktop-nav-wrapper"> <h3 id="desktop-logo" class="logo"><a href="/">Logo </a></h3> <nav> <ul id="desktop-nav-content"> <li id="mobile-menu-link"><a>Menu</a></li> </ul> </nav> </div> </div>似乎是一个字符串。在这里

@post

应该是

@post = params[:post_id]

Answer 3

您应该找到自己的帖子，而不要传递id：

@post = Post.find(params[:post_id])

另外，考虑使用counter_cache存储点赞的次数-就性能而言要好得多！ https://guides.rubyonrails.org/association_basics.html#options-for-belongs-to-counter-cache

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3 个答案: